Steam-engine indicator



PATENTED FEB. 16, 1904.

C. B. BOSWORTH.

STEAM ENGINE INDICATOR.

APPLICATION FILED FEB. 14. 1903.

2 SHEETS-SHEET 2.

N0 MODEL WITHES 5E5 UNITED STATES Patented February 16, 1904.

PATENT OEEIcE.

CHARLES B. BOSWORTH, OF BOSTON, MASSACHUSETTS, ASSIGNOR TO STAR BRASS MANUFACTURING COMPANY OF BOSTON, MASSACHU- SETTS, A CORPORATION OF MASSACHUSETTS.

STEAM-ENGINE INDICATOR.

SPECIFICATION forming part of Letters Patent No. 752,197, dated February 16, 1904. Application filed February 14:, 1903. Serial No. 143,366. (No model.)

To all whom it may concern.-

Be it known that I, CHARLEs B. Boswonrn, a citizen of the United States, residing at Boston, in the county of Suffolk and State of Massachusetts, have invented a new and useful Improvement in Steam-Engine Indicators, of which the following is a full, clear, and exact description, reference being had to the accompanying drawings, forming a part of this specification, in explaining its nature.

The invention relates to a steam-engine indicator which is in some respects an improvement upon that described in my Letters Patent of the United States No. 687,391, dated November 26, 1901.

The present invention consists in various modifications whereby the spring is removed from the cylinder or steam-chamber and combined with the piston-rod outside the chamher and where it is subjected only to variations in the temperature of the surrounding atmosphere.

The invention relates to means for coupling the spring to the piston-rod; to means for preventing live steam and heat therefrom from reaching the spring; to the cylinder, steamchamber, and manner of mounting the cylinder in the chamber, whereby it is made removable for the purpose of permitting cylinders and pistons varying in diameterto be substituted therefor, and also to means for adjusting the penci1-lever with respect to the piston-rod.

I will now describe the invention in connection with the drawings forming a part of this specification, Wherein Figure 1 is a view of an indicator having the features of my invention, representing the portion to which it relates in vertical central section. Fig. 2 is a vertical section, enlarged, of a portion thereof. Fig. 3 is a view in horizontal section upon the dotted line 3 3 of Fig. 2.

In the drawings, A is the plate upon which the drum A is mounted. The plate extends horizontally from a cylindrical casing a, a portion of which is above the level of its upper surface, but the main part of which extends below the level of its lower surface. The casing contains the chambers a a separated from each other by the horizontal partition a The chamber (0 opens at its top, the opening being closed by the head or cap a The casing (4 also has openings a in its wall (see Fig. 3) to connect the chamber a with the outer air. In the chamber is a portion of the piston-rod 5 and the piston-spring 6. The piston-rod extends from the piston B in the chamber of the cylinder C through a bushing 6 contained in a hole a in the diaphragm (6. It is made in two principal parts-viz., the part 6, which is attached to the piston and extends into the chamber a, and the part b", which is a continuation from the end of the part 6 Both parts are hollow, and the part 7)" is connected to the part Z2 by a coupling 6 which also serves to couple the spring 6' to the pistonrod. The shape of the coupling is best represented in Figs. 2 and 3. It comprises a head 6, from which extends downward a hollow stem 5 threaded upon its exterior and interior. The hole in the stem extends through the head 5. The stem screws into the threaded end of the part Z) of the piston until the head seats against the end of this part. In the threaded hole of the stem is the screw 7), the head 5 of which is presented downward in the hollow r" of the piston-rod section 6". Its upper end I) is preferably cup-shaped, extends to or above the level of the head 6, and bears against the ball 7) upon the foot-bar 6 of the spring 6. The spring is wound from the foot-bar in the usual manner to form a double coil. Its upper ends are attached to the adjustable holder 6 in the usual way, and the holder is of ordinary type and adjustable upon the threaded stem 6 extending downward from the head (0 in the usual manner and for the usual purposes. The piston and spring-coupling Z2 also has extending upward from its head 6 a conical extension 6 which has a threaded hole 6 extending downward from its upper end to the head, a recess 5 extending downward to the head and dividing the extension into two parts and of a width to receive the foot 6 of the spring and an upper end 5 cylindrical in shape excepting as it is cut by the recess and adapted to enter an annular recess 6 in an extension from the part 6 of the piston-rod and to be surrounded by a reinforcing-sleeve If, extending downward from said extension. The portion Z) of the piston-rod also has the threaded section I) below the enlargement and which screws into the threaded hole 5 of the coupling. Its under surface 6 is cup-shaped and the threaded portion is of suflicient length to act to hold the spring-ball Z2 between it and the screw 6 It will thus be seen that the coupling 7) serves to rigidly connect together the two parts of the piston-rod and at the same time serves to couple the spring to the piston-rod and to afford means whereby the spring may be rigidly secured to the piston-rod and may always be maintained so secured, this result being reached by means of the screw 7), which is always adjustable through the hollow 5 of the part L of the piston-rod and which serves to clamp the ball which forms one part of the spring-joint against the lower end of the part b of the piston-rod.

It will be observed that the spring is used in its capacity as a draw-spring rather than as a compression-spring and that therefore the action of the stem upon the piston serves to extend the spring and to cause the ball of the foot to bear against the lower end of the part b of the piston, and as the ball or its bearing wears lost motion is prevented by setting the ball tightly against its seat by means of the screw 6 The part b of the piston-rod extends through a hole in the cap or head a, and its hollow is enlarged from its upper end downward for quite a distance. It is interiorly threaded about this enlarged hole and there screws into it the long threaded sleeve 7), the outer end of which is provided with the flaring extension Z2 recessed to form ears for receiving a turning instrument. The sleeve is very nearly of the length of the enlarged hole, and in it is the rod 5 which is attached to it by its enlargement 6 at its upper end and by the nut I) at its lower end, which screws against the lower end of the sleeve. This rod serves as a part of the connection between the piston-rod and the pencil-lever D, the remaining part of the connection being by means of the link (Z. By turning the sleeve 6 the rod 6 is adjusted lengthwise the piston-rod, and con sequently adjusts the relation of the pencillever D with respect to the piston-rod. The advantage of this connection over that described in my patent arises from the fact that a much longer bearing between the adjusting parts is secured, and this reduces the wear and the liability of lost motion. The pencillever is otherwise hung as described .in my said patent.

As I have said, the spring 6 is contained in thechamber a, which opens to the atmosphere through the openings (/1 so that the spring is subjected to the atmosphere and is thereby prevented from becoming unduly heated. To further prevent the heating of the spring, I have arranged that any escape of steam from the chamber (a shall not enter the chamber a, but shall be deflected from it. Ordinarily some steam will follow the piston-rod, and if there were no provision for deflecting it it would enter the chamber a. I have trapped this steam, however, by forming in the bushing 7f outward-extending channels a, which extend from the piston-rod to an annular chamber E, which surrounds the bushing and which has one or more escapepassages 0' through the casing to the outer air. Steam following the piston escapes through the bushing into the chamber or trap 11 and thence to the outer air, and is thus prevented from reaching the chamber a.

The bushing If may be made in two parts, if desired, which may be separated from each other, so as to form a continuous connection between the piston-rod and the trap E, if desired.

The chamber a is of sufl'icient length to hold the cylinder C in the part which is below the line of the steam-inlet f to the chamber. This aifords opportunity for the full head of steam to reach the open end of the cylinder and to bear equally upon all parts of the piston. The cylinder G is open at both ends and is represented as secured within the chamber a", which is open at its lower end. The cylinder is fastened to the casing by means of the flange oat its lower end and the clamping-nut c, which clamps the flange against the lower end of the casing a, the clamp having an interiorlythreaded sleeve which screws upon an exterior thread of the casing. The clamping-nut also has the central hole 0 extending through it. The diameter of the cylinder is enough less than that of the portion of the chamber in which it is contained to provide a cylindrical extension g of the chamber a about it and which opens at its upper end into the chamber (f. This permits steam from the chamber a to constantly surround the piston, and thus equalize the temperature of its inner and outer surfaces. The cylinder is centrally held by the part '0 at its lower end, which is of a size to fit the bore of the chamber (0 The piston B is of the usual type, and the piston-rod extends through it and is connected with it by a shoulder on its lower side. As this part of the piston-rod is screwed upon the stem of the piston-rod coupling, its lower end is made hexagonal in order that it may turn in the piston and in the bushing and from outside the indicator-casing in screwing it upon the coupler-stem. The end of the piston-rod is accessible through the hole in the cylinder clamping-nut and through the open end of the cylinder, and the head of the spring binding-screw is also accessible through this opening and the bore of the open-ended piston-rod. The piston, it will be seen, is subjected to steam-pressure upon one side and to the pressure of the atmosphere upon the other,

and any steam working by the piston escapes into the atmosphere and exerts no influence upon the piston.

Having thus fully described my invention, I claim and desire to secure by Letters Patent of the United States 1. In a steam-engine indicator, in combination with a pencil movement and an open cylinder, a piston contained in said cylinder, a steam-supply chamber and a spring-holding chamber between the cylinder and piston and the pencil movement, the said chambers being separated from each other by a diaphragm, the spring-chamber being open to the surrounding air,the piston-rod in two parts connecting the piston with the pencil movement and extending through both chambers, a spring contained in the spring-holding chamber, and a coupling connecting the two parts of the piston-rod together and also the spring to the piston-rod.

2. In a steam-engine indicator, a casing forming a steam-chamber and a spring-chamber open to the outer air, a diaphragm separating said chambers from each other, a piston contained in said steam-chamber, a spring contained in said spring-chamber, a pencil movement, a piston-rod extending to pass through said diaphragm and spring-chamber to connect with said pencil movement, and means for detachably combining said spring with said piston-rodand casing.

3. In a steam-engine'indicator, a piston-rod in two parts connecting the piston with the pencil movement, a spring, and a coupling connecting the two parts of the piston-rod together, comprising a head having on one side a threaded stem screwing into one part of the piston-rod and upon the other a threaded, tubular extension screwing onto the end of the other part of the piston-rod, the said lastnamed part also having an integral sleeve which laps upon the extension.

4:. In a steam-engine indicator, a piston-rod in two parts connecting the piston with the pencil movement, a coupling connecting the two parts, a spring the foot of which is held between the two parts and prevented from turning by the coupling, and a clampingscrew to clamp the foot against one of the parts, the head of which is accessible through the open end of one of the parts of the pistonrod.

5. In asteam-engine indicator, the combination of a cylinder-chamber, a spring-chamber, a diaphragm interposed between said cylinder and spring chambers, a bushing carried by said diaphragm having an interior annular channel provided with outlets entering into a surrounding chamber formed in said diaphragm, which chamber has one or more outlets to the outer air, a piston contained in said cylinder-chamber and a piston-rod secured thereto and extending through the bushing carried by said diaphragm, substantially as and for the purposes set forth.

6. In a steam-engineindicator, a easinghaving a spring-chamber open to the atmosphere, a spring contained therein, a steam-chamber having a steam-inlet in its upper end and open at its lower end, a diaphragm, separating said steam and spring chambers, a detachable cylinder contained in said steam-chamber, a piston carried by said cylinder, a pencil movement, a piston-rod in two parts connecting with the pencil movement, one part of which rod is removable with said piston, and means for combining the two parts of the piston-rod together within said spring-chamber and for detachably securing one end of the aforesaid spring to the same.

7. In a steam-engine indicator, a casing having a spring-chamber open to the atmosphere, a steam-chamber, a diaphragm separating said steam and spring chambers, a detachable cylinder contained in said steam chamber of somewhat lesser diameter, a piston carried by said cylinder, a pencil movement, a pistonrod extending from said piston to pass through said diaphragm and spring-chamber to connect with said pencil movement, a draft-spring one end of which is adjustably combined with said casing, and means for securing the two parts of the piston-rod together and the other end of said spring thereto.

8. In a steam-engine indicator, a case having a steam-chamberopen at its lower end and having a steam-inlet at its upper end, a cylinder open at both ends contained in the lower part of said chamber, a piston-rod in two parts, a coupling between the two parts, having a threaded stem into which the end of one part of the piston-rod screws, and a part having a head to bear against the piston and a threaded end to engage said coupling.

9. In a steam-engine indicator having a cylinder, a piston contained in the cylinder, a piston-rod in two parts connecting the piston with the pencil movement, a spring secured to the piston-rod between its two parts, a coupling connecting the two parts having a threaded stem, and a spring combining-screw, the part of the piston-rod connecting the piston with the coupling having an outer end and the combining-screw having a head, both in exposed positions.

10. In a steam-engine indicator, the pistonrod having formed in its outer end a hole the wall of which is threaded, a threaded sleeve to screw in said hole, having means at its outer end for turning it, and a rod attached to said sleeve in a manner to hold it from end'wise movement, but to permit its turning therein, the pencil-lever, and a link connecting the rod with the pencil-lever.

CHARLES E. BOSVVORTH.

VVitnesses':

F. F. RAYMOND, 2d, J. W. DOLAN. 

